The Impact of Low-Level Iron Supplements on the Faecal Microbiota of Irritable Bowel Syndrome and Healthy Donors Using In Vitro Batch Cultures

Abstract

Ferrous iron supplementation has been reported to adversely alter the gut microbiota in infants. To date, the impact of iron on the adult microbiota is limited, particularly at low supplementary concentrations. The aim of this research was to explore the impact of low-level iron supplementation on the gut microbiota of healthy and Irritable Bowel Syndrome (IBS) volunteers. Anaerobic, pH-controlled in vitro batch cultures were inoculated with faeces from healthy or IBS donors along with iron (ferrous sulphate, nanoparticulate iron and pea ferritin (50 μmol−1 iron)). The microbiota were explored by fluorescence in situ hybridisation coupled with flow cytometry. Furthermore, metabolite production was assessed by gas chromatography. IBS volunteers had different starting microbial profiles to healthy controls. The sources of iron did not negatively impact the microbial population, with results of pea ferritin supplementation being similar to nanoparticulate iron, whilst ferrous sulphate led to enhanced Bacteroides spp. The metabolite data suggested no shift to potentially negative proteolysis. The results indicate that low doses of iron from the three sources were not detrimental to the gut microbiota. This is the first time that pea ferritin fermentation has been tested and indicates that low dose supplementation of iron is unlikely to be detrimental to the gut microbiota.

Hydrolysis of pea protein differentially modulates its effect on iron bioaccessibility, sulfur availability, composition and activity of gut microbial communities in vitro

“…7 Consistent with findings by Dostal et al 33 in rodents, iron salt addition led to greater total SCFAs production in colon as a likely result of enhanced bacteria metabolic activity. However, we found that such increase in total SCFAs resulted in altered ratios over favouring acetate (86% of total SCFAs in Fe versus 47% in the fermented treatments without Fe), which was also observed by Poveda et al 34 This may be suggestive of selective enrichment in acetogenic species under iron fortification in vitro , which is supported by our findings of significant higher total aerobic bacteria count in the presence of Fe. Total aerobic count can indicate an increase in facultative anaerobes such as Enterococcaceae and Enterobacteriaceae , which are known acetate producers 35 and identified as LEfSe biomarkers for Fe in this study.…”

Adults with Prader–Willi syndrome exhibit a unique microbiota profile

“…De-identified 16S profiles from usual diet/non-interventional fecal samples of 25 adults (34.9 ± 10.2 years; 60% female) with genetically confirmed PWS and residing in Florida [ 3 , 12 ] were compared to those of healthy adults residing in Canada (n = 151; 35.2 ± 10.1 years; 61% female) [ 13 ], adults with IBS residing in Canada (n = 263; 41.8 ± 15.2; 79% female) [ 14 ], healthy young adults residing in Florida, USA (n = 68; 23.2 ± 3.5; 63% female) [ 15 ], and healthy older women residing in Florida (n = 26; 73.7 ± 5.6 years) [ 16 ]. All source data originated from the same lab environment and were subsequently treated with the same bioinformatics processing.…”

Cranberry Arabino-Xyloglucan and Pectic Oligosaccharides Induce Lactobacillus Growth and Short-Chain Fatty Acid Production

“…Additionally, a vessel without any substrate was used as negative control. Batch culture fermentations were incubated for 48 h with gentle stirring, and samples were collected at times 0 h, 24 h and 48 h. Fluorescence in situ hybridization (FISH) analysis was performed in conjunction with flow cytometry (Flow FISH) as described previously, each sample was analyzed once and the triplicate data were used to calculate the mean and standard deviation [ 39 ]. Short chain fatty acid analysis was performed using a previously described modified derivatization method, again, each sample was analyzed once and the triplicate data were used to calculate the mean and standard deviation [ 39 ].…”